Earnings Per Share (Schedule of Earnings Per Share, Basic and Diluted) (Details) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended								12 Months Ended
	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2013	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Class of Stock [Line Items]
Income (loss) from continuing operations, net of tax									$ 789	$ 284	$ (960)
Weighted Average Number of Shares Outstanding, Basic (in shares)									720	743	755
Income (Loss) from Continuing Operations, Per Basic Share	$ 0.29	$ 0.68	$ 0.20	$ (0.07)	$ (0.23)	$ 0.23	$ 0.22	$ 0.15	$ 1.10	$ 0.38	$ (1.27)
Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants (in shares)									1	1	0
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements (in shares)									3	4	0
Income (Loss) From Continuing Operations Diluted									$ 789	$ 284	$ (960)
Weighted Average Number of Shares Outstanding, Diluted (in shares)									724	748	755
Income (Loss) from Continuing Operations, Per Diluted Share	$ 0.29	$ 0.67	$ 0.20	$ (0.07)	$ (0.23)	$ 0.23	$ 0.22	$ 0.15	$ 1.09	$ 0.38	$ (1.27)
RSUs
Class of Stock [Line Items]
Income (Loss) from Continuing Operations, Per Diluted Share									$ (0.01)